* Moreover the inferred type is closer to the expected one.
*)
C.LetIn (n,s',t'),CicSubstitution.subst s' inferredty,
- subst',metasenv',ugraph2
+ subst'',metasenv'',ugraph2
| C.Appl (he::((_::_) as tl)) ->
let he',hetype,subst',metasenv',ugraph1 =
type_of_aux subst metasenv context he ugraph
(match outtype with
| C.Meta (n,l) ->
- (let candidate,ugraph5,metasenv =
+ (let candidate,ugraph5,metasenv,subst =
let exp_name_subst, metasenv =
let o,_ =
CicEnvironment.get_obj CicUniv.empty_ugraph uri
add_lambdas (Cic.Meta (new_meta,irl))
arity_instantiated_with_left_args
in
- (Some candidate),ugraph4,metasenv
+ (Some candidate),ugraph4,metasenv,subst
| (constructor_args_no,_,instance,_)::tl ->
try
- let instance' =
- CicSubstitution.delift constructor_args_no
- (CicMetaSubst.apply_subst subst instance)
+ let instance',subst,metasenv =
+ CicMetaSubst.delift_rels subst metasenv
+ constructor_args_no instance
in
- let candidate,ugraph,metasenv =
+ let candidate,ugraph,metasenv,subst =
List.fold_left (
- fun (candidate_oty,ugraph,metasenv)
+ fun (candidate_oty,ugraph,metasenv,subst)
(constructor_args_no,_,instance,_) ->
match candidate_oty with
- | None -> None,ugraph,metasenv
+ | None -> None,ugraph,metasenv,subst
| Some ty ->
try
- let instance' =
- CicSubstitution.delift
- constructor_args_no
- (CicMetaSubst.apply_subst subst instance)
+ let instance',subst,metasenv =
+ CicMetaSubst.delift_rels subst metasenv
+ constructor_args_no instance
in
- let b,ugraph1 =
- CicReduction.are_convertible context
- instance' ty ugraph
+ let subst,metasenv,ugraph =
+ fo_unif_subst subst context metasenv
+ instance' ty ugraph
in
- if b then
- candidate_oty,ugraph1,metasenv
- else
- None,ugraph,metasenv
- with Failure s -> None,ugraph,metasenv
- ) (Some instance',ugraph4,metasenv) tl
+ candidate_oty,ugraph,metasenv,subst
+ with
+ CicMetaSubst.DeliftingARelWouldCaptureAFreeVariable
+ | CicUnification.UnificationFailure _
+ | CicUnification.Uncertain _ ->
+ None,ugraph,metasenv,subst
+ ) (Some instance',ugraph4,metasenv,subst) tl
in
match candidate with
- | None -> None, ugraph,metasenv
+ | None -> None, ugraph,metasenv,subst
| Some t ->
let rec add_lambdas n b =
function
in
Some
(add_lambdas 0 t arity_instantiated_with_left_args),
- ugraph,metasenv
- with Failure s ->
- None,ugraph4,metasenv
+ ugraph,metasenv,subst
+ with CicMetaSubst.DeliftingARelWouldCaptureAFreeVariable ->
+ None,ugraph4,metasenv,subst
in
match candidate with
| None -> raise (Uncertain "can't solve an higher order unification problem")
| Some candidate ->
- let s,m,u =
+ let subst,metasenv,ugraph =
fo_unif_subst subst context metasenv
candidate outtype ugraph5
in
C.MutCase (uri, i, outtype, term', pl'),
- (Cic.Appl (outtype::right_args@[term'])),s,m,u)
+ CicReduction.head_beta_reduce
+ (CicMetaSubst.apply_subst subst
+ (Cic.Appl (outtype::right_args@[term']))),
+ subst,metasenv,ugraph)
| _ -> (* easy case *)
let _,_, subst, metasenv,ugraph5 =
type_of_aux subst metasenv context
(subst,metasenv,ugraph5) outtypeinstances
in
C.MutCase (uri, i, outtype, term', pl'),
- CicReduction.whd ~subst context
- (C.Appl(outtype::right_args@[term])),
+ CicReduction.head_beta_reduce
+ (CicMetaSubst.apply_subst subst
+ (C.Appl(outtype::right_args@[term]))),
subst,metasenv,ugraph6)
| C.Fix (i,fl) ->
let fl_ty',subst,metasenv,types,ugraph1 =
type_of_aux' metasenv context term ugraph
with
CicUniv.UniverseInconsistency msg -> raise (RefineFailure msg)
+
+(*CSC: this is a very very rough approximation; to be finished *)
+let are_all_occurrences_positive uri =
+ let rec aux =
+ (*CSC: here we should do a whd; but can we do that? *)
+ function
+ Cic.Appl (Cic.MutInd (uri',_,_)::_) when uri = uri' -> ()
+ | Cic.MutInd (uri',_,_) when uri = uri' -> ()
+ | Cic.Prod (_,_,t) -> aux t
+ | _ -> raise (RefineFailure "not well formed constructor type")
+ in
+ aux
+let typecheck metasenv uri obj =
+ let ugraph = CicUniv.empty_ugraph in
+ match obj with
+ Cic.Constant (name,Some bo,ty,args,attrs) ->
+ let bo',boty,metasenv,ugraph = type_of_aux' metasenv [] bo ugraph in
+ let ty',_,metasenv,ugraph = type_of_aux' metasenv [] ty ugraph in
+ let subst,metasenv,ugraph = fo_unif_subst [] [] metasenv boty ty' ugraph in
+ let bo' = CicMetaSubst.apply_subst subst bo' in
+ let ty' = CicMetaSubst.apply_subst subst ty' in
+ let metasenv = CicMetaSubst.apply_subst_metasenv subst metasenv in
+ Cic.Constant (name,Some bo',ty',args,attrs),metasenv,ugraph
+ | Cic.Constant (name,None,ty,args,attrs) ->
+ let ty',_,metasenv,ugraph = type_of_aux' metasenv [] ty ugraph in
+ Cic.Constant (name,None,ty',args,attrs),metasenv,ugraph
+ | Cic.CurrentProof (name,metasenv',bo,ty,args,attrs) ->
+ assert (metasenv' = metasenv);
+ (* Here we do not check the metasenv for correctness *)
+ let bo',boty,metasenv,ugraph = type_of_aux' metasenv [] bo ugraph in
+ let ty',sort,metasenv,ugraph = type_of_aux' metasenv [] ty ugraph in
+ begin
+ match sort with
+ Cic.Sort _
+ (* instead of raising Uncertain, let's hope that the meta will become
+ a sort *)
+ | Cic.Meta _ -> ()
+ | _ -> raise (RefineFailure "The term provided is not a type")
+ end;
+ let subst,metasenv,ugraph = fo_unif_subst [] [] metasenv boty ty' ugraph in
+ let bo' = CicMetaSubst.apply_subst subst bo' in
+ let ty' = CicMetaSubst.apply_subst subst ty' in
+ let metasenv = CicMetaSubst.apply_subst_metasenv subst metasenv in
+ Cic.CurrentProof (name,metasenv,bo',ty',args,attrs),metasenv,ugraph
+ | Cic.Variable _ -> assert false (* not implemented *)
+ | Cic.InductiveDefinition (tys,args,paramsno,attrs) ->
+ (*CSC: this code is greately simplified and many many checks are missing *)
+ (*CSC: e.g. the constructors are not required to build their own types, *)
+ (*CSC: the arities are not required to have as type a sort, etc. *)
+ let uri = match uri with Some uri -> uri | None -> assert false in
+ let typesno = List.length tys in
+ (* first phase: we fix only the types *)
+ let metasenv,ugraph,tys =
+ List.fold_right
+ (fun (name,b,ty,cl) (metasenv,ugraph,res) ->
+ let ty',_,metasenv,ugraph = type_of_aux' metasenv [] ty ugraph in
+ metasenv,ugraph,(name,b,ty',cl)::res
+ ) tys (metasenv,ugraph,[]) in
+ let con_context =
+ List.rev_map (fun (name,_,ty,_)-> Some (Cic.Name name,Cic.Decl ty)) tys in
+ (* second phase: we fix only the constructors *)
+ let metasenv,ugraph,tys =
+ List.fold_right
+ (fun (name,b,ty,cl) (metasenv,ugraph,res) ->
+ let metasenv,ugraph,cl' =
+ List.fold_right
+ (fun (name,ty) (metasenv,ugraph,res) ->
+ let ty = CicTypeChecker.debrujin_constructor uri typesno ty in
+ let ty',_,metasenv,ugraph =
+ type_of_aux' metasenv con_context ty ugraph in
+ let undebrujin t =
+ snd
+ (List.fold_right
+ (fun (name,_,_,_) (i,t) ->
+ (* here the explicit_named_substituion is assumed to be *)
+ (* of length 0 *)
+ let t' = Cic.MutInd (uri,i,[]) in
+ let t = CicSubstitution.subst t' t in
+ i - 1,t
+ ) tys (typesno - 1,t)) in
+ let ty' = undebrujin ty' in
+ metasenv,ugraph,(name,ty')::res
+ ) cl (metasenv,ugraph,[])
+ in
+ metasenv,ugraph,(name,b,ty,cl')::res
+ ) tys (metasenv,ugraph,[]) in
+ (* third phase: we check the positivity condition *)
+ List.iter
+ (fun (_,_,_,cl) ->
+ List.iter (fun (_,ty) -> are_all_occurrences_positive uri ty) cl
+ ) tys ;
+ Cic.InductiveDefinition (tys,args,paramsno,attrs),metasenv,ugraph
(* DEBUGGING ONLY
let type_of_aux' metasenv context term =